(1) Field of the Invention
The present invention relates to a water-soluble resin emulsion in which water-soluble polymers which are incompatible with each other are made stably compatible, and a process for the preparation of this emulsion.
The water-soluble resin emulsion of the present invention has a combination of the characteristics of water-soluble polymers used together as the protecting colloid, and therefore, can manifest characteristic performances not found in known materials.
(2) Description of the Related Art
For example, gelatin has heretofore been used as a photosensitive material for the production of a color filter, but an aqueous solution of gelatin is inherently defective in that the coating property is poor and it is difficult to uniformly coat the aqueous solution. Gelatin is also used as a material for the silver salt photography, but when gelatin alone is used, the mechanical strength is too low, and especially during the developing treatment or the like, scratches are easily formed in the wet state. Nevertheless, when gelatin is used in the form of a water-soluble emulsion containing gelatin and saponified polyvinyl acetate, a photosensitive material for the preparation of a color filter, a material for silver salt photography and a photosensitive material for screen printing, which have an excellent coating property and mechanical strength, can be obtained.
Furthermore, by rendering water-soluble polymers, the combined use of which is difficult because of a poor compatibility therebetween, compatible with each other, an excellent topcoating, an excellent prime-coating, an excellent material for a synthetic leather can be obtained.
Nevertheless, the conventional polymer-modifying techniques for compatibilizing incompatible water-soluble polymers are defective in that a complicated recipe is necessary and the kinds of water-soluble polymers that can be compatibilized are considerably limited. Accordingly, it is difficult to stably compatibilize desired incompatible water-soluble polymers and obtain a material having a combination of the characteristics of both of the water-soluble polymers.
SUMMARY OF THE INVENTION
Therefore, a primary object of the present invention is to solve the foregoing problems of the conventional techniques and provide a water-soluble resin emulsion formed by stably compatibilizing at least two incompatible water-soluble polymers and a process for the preparation of this water-soluble resin emulsion.
In accordance with one aspect of the present invention, this object can be attained by a water-soluble resin emulsion formed by stably compatibilizing at least two incompatible water-soluble polymers by emulsion-polymerizing a monomer having a reactive unsaturated group in the presence of the incompatible water-soluble polymers as the protecting colloid.
In accordance with another aspect of the present invention, there is provided a process for the preparation of a water-soluble emulsion, which comprises emulsion-polymerizing a monomer having a reactive unsaturated monomer in the presence of at least two incompatible water-soluble polymers as the protecting colloid.